Distance measurement modules have long been a crucial technique in industrial applications, and are prevalent in applications including mobile robots, automated-guided vehicles (AGVs), product line inspections and industrial safety gratings. According to measuring techniques, current non-contact distance sensors are segmented into two types—a time of flight estimation method and a triangulation location method. The time of flight estimation method usually provides preferred accuracy and viewable angle than the triangulation location method. However, for calculating a time that light needs for traveling to and fro, the time of flight estimation method requires highly precise and extremely costly mechanism designs.
For applications of AGVs and safety gratings, the precision and viewable angle for sensing distance information are usually not regulated by strict standards. It infers that, when products based on the time of flight are adopted for the applications of AGVs and safety gratings, these over-qualified products are rather utilized for less significant positions such that implementation costs are in equivalence wasted.